Influence of late reopening of the infarct-related artery on left ventricular remodelling after myocardial infarction. IRIS Study Group.
OBJECTIVE
This trial was undertaken to assess the impact of late reopening of the infarct-related artery on left ventricular remodelling in post-myocardial infarction patients.


METHODS
One hundred and fifty seven patients with recent myocardial infarction were routinely submitted to delayed (second week) catheterization. They also underwent systematic angioplasty of a significantly narrowed infarct-related artery with a suitable anatomy, or reopening of a totally occluded infarct-related artery, and repeat follow-up catheterization after 4 months. Changes in left ventricular ejection fraction, left ventricular volumes, and percent of regional hypokinesia were assessed over the study period.


RESULTS
One hundred and thirty-two patients had two interpretable left ventriculograms and two interpretable coronary angiograms. At initial angiography, 56 out of 96 patients with a patent infarct-related artery were successfully submitted to percutaneous coronary angioplasty, of whom 25 had restenosis and eight had total reocclusion at follow-up angiography. Percutaneous transluminal coronary angioplasty was not attempted in the remaining 40 patients due to unsuitable anatomy in 18 or a nonsignificant lesion in 22. The infarct-related artery was totally occluded in 36 patients at initial angiography, and successfully reopened by means of angioplasty in 19, of whom seven showed a reocclusion at follow-up angiography. The independent predictors of left ventricular enlargement, identified by means of multivariate regression analysis, were initial stroke volume index < 40 ml.m-2 (odds ratio = 6.3, 95% confidence interval = [2.5; 16.6]), initial end-systolic volume index > 50 ml.m-2 (odds ratio = 7.1, 95% confidence interval = [1.5; 25.8]), anterior infarct location (odds ratio = 4.1, 95% confidence interval = [1.4; 11.5]) and reocclusion of the infarct-related artery (odds ratio = 7.3, 95% confidence interval = [1.3; 27.3]). Angioplasty of a patent but significantly narrowed infarct-related artery was not found predictive.


CONCLUSIONS
This study demonstrates that reocclusion of a previously open infarct-related artery, as well as the initial low stroke volume index, enlarged end-systolic volume index and anterior infarct location are independent predictors of long-term left ventricular enlargement. These results emphasize the impact of long-term sustained patency of the infarct-related artery on the prevention of left ventricular dysfunction. The need for a larger randomized trial is recognised.
Meneveau
N
N
Hôpital Universitaire Saint-Jacques, Besançon, France.
Bassand
J P
JP
Bauters
C
C
Rozand
J Y
JY
Petit
J L
JL
Beurrier
D
D
Grollier
G
G
Andre
F
F
Vahanian
A
A
Viel
J F
JF
D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use; D000368:Aged; D015906:Angioplasty, Balloon, Coronary; D016009:Chi-Square Distribution; D017023:Coronary Angiography; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009203:Myocardial Infarction / Q000188:drug therapy / Q000503:physiopathology / Q000628:therapy*; D015912:Thrombolytic Therapy; D013997:Time Factors; D016896:Treatment Outcome; D014654:Vascular Patency; D016277:Ventricular Function, Left
D000319:Adrenergic beta-Antagonists